I have one of the Mantis shrimp I got off my live rock in a seperate tank but man do i have a lot of noisy stuff in my main. Went to sleep last night "FINALLY" to the sounds of a demolition crew hard at work in their. I suspect i have several more Mantis shrimp in their, It honestly sounded like someone was beating the wall down with a sledge hammer and banging rocks together. This was some of the wildest stuff I've ever had to hear. I also have several bristle worms in the 4-8 inch range.